Lubricant-related performance characteristics such as high temperature deposit and varnish control, fuel economy and wear protection are extremely advantageous attributes as measured by a variety of bench and engine tests. It is known that selection of viscosity modifier can significantly impact a lubricant formulation's viscosity control over a wide temperature range as well as fuel efficiency. It is also known that addition of viscosity modifiers can also contribute to sludge and deposit formation. Other than viscometric effects, selection of viscosity modifier is not generally expected to have a significant impact on wear performance, while other formulation components, such as ZDDP antiwear and friction modifiers, do.
Therefore, a major challenge in engine oil formulation is simultaneously achieving wear, deposit, and varnish control while also maintaining fuel economy performance, over a broad temperature range.
Lubricant-related wear control is highly desirable due to increasing use of low viscosity engine oils for improved fuel efficiency. As governmental regulations for vehicle fuel consumption and carbon emissions become more stringent, use of low viscosity engine oils to meet the regulatory standards is becoming more prevalent. At the same time, lubricants need to provide a substantial level of durability and wear protection due to the formation of thinner lubricant films during engine operation. As such, use of antiwear additives and friction modifiers in a lubricant formulation is the typical method for achieving wear control and durability. Due to limitations of using high levels of antiwear and friction modifier additives such as catalyst poisoning and deposit formation, it is highly desirable to find alternative methods for achieving excellent wear control and durability.
A major challenge in engine oil formulation is simultaneously achieving high temperature wear control while also maintaining or improving deposit, sludge and varnish control and fuel economy.
Despite the advances in lubricant oil formulation technology, there exists a need for an engine oil lubricant that effectively improves wear control while maintaining or improving deposit control and fuel efficiency.